The main difference between <a4j:push> and
<a4j:poll> components is that <a4j:push> makes request to
minimal code only (not to JSF tree) in order to check the presence of
messages in the queue. If the message exists the complete request will
be performed. The component doesn't poll registered beans but
registers EventListener which receives messages about events.

Attribute 'interval' is used as for poll component. It
specifies the interval in ms. for call push request. Simple example of
usage: